The Z7U throttle spool seen here and the one Jim has use the same mounting points but you have to get creative with the top of the water pump because it's designed for a different generation of pump which is in a slightly different position. Other than that, it's pretty simple. They don't always have that spring, BTW.
The throttle cable enters from the rear right, and on the GTA the cable really does swoop around to the back of the engine bay in order to attach. I have a 60mm piece of 8mm stainless rod drilled from each end to a depth of about 28mm with a 6mm bit, and then a centre bore of 2mm. I can then conjoin a new outer sheath with the original to lengthen it and replace the entire inner cable. I then sheath the joinwith electrical heat-shrink to keep moisture out.
I've got another Z7U manifold spare now if anyone wants one.